Effects of alternative thinning regimes and prescribed burning in natural, even-aged loblolly-shortleaf pine stands: 25 year results

In southeastern Arkansas, pine growth was monitored for 19 yr after mechanically strip thinning a dense, naturally regenerated, even-aged stand of 6-yr-old loblolly pines (Pinus taeda L) and shortleaf pines (P. echinata Mill.) that averaged 16,600 stems/ac. Prescribed winter burns were conducted biennially between ages 9 and 20 yr and at 24 yr. Commercial thinnings during the 17th and 23rd growing seasons left a residual stocking of either 85ft(2)/ac or 200 crop trees/ac (75ft(2)/ac) in merchantable-sized (>3.5 in. dbh)pines on plots that were precommercially thinned and on plots that were not. Precommercial thinning enhanced pine growth in dbh and sawlog volume through 25 yr. Because of increased sawlog production, present net value averaged highest on plots that were precommercially thinned at age 6 then commercially thinned during the 17th yr to 200 crop trees/ac and during the 23rd yr to 75 ft(2)/ac. In the year following prescribed winter burns, both dbh growth and volume growth were reduced by about one-half when crown scorch was 75%. South. J. Appl. For. 27(1):18-29.